From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8EE33246788; Mon, 28 Sep 2026 00:17:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790554680; cv=none; b=GE0/DKeKPOmaA7v36+aYLKSlF/N36GSBSpjVLsVxkdNpQxq2CAw5hSrQ+W/nLbqnfX5B/8CbtMsPYp+v1NZ4MgP/NsYoL+WGTYb1yiYFShedfYsOQWO+iu3F+yPeRekFaF+raOVx5NuF40WgzNwBQ1COTywe5ywuKQNwuCHrLPQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790554680; c=relaxed/simple; bh=SQrhgKaTPMx1AI8+vN/pA3pIoyGE2f9oz8iUxF25JU8=; h=Message-ID:Date:MIME-Version:Subject:To:References:Cc:From: In-Reply-To:Content-Type; b=FG8/QwOInL3r8uR/R9q3aUyAo6/CZsBr9JNyuywL04xr4JfIvgEIxTsnl4d+O5B+EiuH901GSJKhMIRvnT9qvOQFd0Ybm0MPM5dCAhSc8Ua2gIYh1avAo/R3eNf+vEVN5zHCe2DUR5rHYpQRRwvotfyJv0MgnBZiJT9X/Z7YhO0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SiOeEEbe; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SiOeEEbe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 780701F00899; Mon, 28 Sep 2026 00:17:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790554679; bh=BrvjgngQVWWsLu8FybQ5949ekW2GT1BmcozWeYv5iBo=; h=Date:Subject:To:References:Cc:From:In-Reply-To; b=SiOeEEbe8GD/H8hvlMJPAymuwbvZGf4VKIRo+AnDu92s5DARo7VpUXKQINbb9P4qv c/SBdEGZG2vHvhuU1fYYEY/JeSb1j3e5ULeX6zME3kIXY0O1JJ7nZ71C1Wwx/nzf/v YYqRqAYwkkpmkDf+UCmAK69f7uFlJ0Dvtk0rjnHLNJzx3Kh5u97XH0iZiX/IguYe5Z 9X9Cp9Y9GSwLkq69sx1m3Dy21tPolE8owVQtH2u1a6yxbgkCTvf7zrUQdeM/NDVIoZ QOVK0H9bUGug2hkS59JnxK67ItlNJec2PR0fzdj47dvbxBG31v9PSkG8peOOqcCiSX vPVTw0QRCeKdA== Message-ID: <944e99e2-c927-43cc-b4d5-f810a31cce96@kernel.org> Date: Mon, 28 Sep 2026 08:17:55 +0800 Precedence: bulk X-Mailing-List: fstests@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 10/13] fstests: verify IMA isolation on cloned filesystems To: Zorro Lang References: Content-Language: en-US Cc: fstests@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, djwong@kernel.org From: Anand Suveer Jain In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/9/26 03:58, Zorro Lang wrote: > On Sat, Jul 25, 2026 at 03:39:07PM +0800, Anand Jain wrote: >> Add testcase to verify IMA measurement isolation when multiple devices >> share the same FSUUID. >> >> Signed-off-by: Anand Jain >> --- >> tests/generic/804 | 108 ++++++++++++++++++++++++++++++++++++++++++ >> tests/generic/804.out | 10 ++++ >> 2 files changed, 118 insertions(+) >> create mode 100644 tests/generic/804 >> create mode 100644 tests/generic/804.out >> >> diff --git a/tests/generic/804 b/tests/generic/804 >> new file mode 100644 >> index 000000000000..ced32e6d79dd >> --- /dev/null >> +++ b/tests/generic/804 >> @@ -0,0 +1,108 @@ >> +#! /bin/bash >> +# SPDX-License-Identifier: GPL-2.0 >> +# Copyright (c) 2026 Anand Jain . All Rights Reserved. >> +# >> +# FS QA Test 804 >> +# Verify IMA isolation on cloned filesystems: >> +# . Mount two devices sharing the same FSUUID (cloned). >> +# . Apply an IMA policy to measure files based on that FSUUID. >> +# . Create unique files on each mount point to trigger measurements. >> +# . Confirm the IMA log correctly attributes events to the respective mounts. >> + >> +. ./common/preamble >> +. ./common/filter >> + >> +_begin_fstest auto quick clone >> + >> +_require_test >> +_require_block_device $TEST_DEV >> +_require_loop >> + >> +_fixed_by_fs_commit btrfs xxxxxxxxxxxx \ >> + "btrfs: use on-disk uuid for s_uuid in temp_fsid mounts" >> +_fixed_by_fs_commit btrfs xxxxxxxxxxxx \ >> + "btrfs: derive f_fsid from on-disk fsuuid and dev_t" >> + >> +_cleanup() >> +{ >> + cd / >> + rm -r -f $tmp.* >> + _unmount $mnt1 2>/dev/null >> + _unmount $mnt2 2>/dev/null >> + _loop_image_destroy "${devs[@]}" 2> /dev/null >> +} >> + >> +# Normalize device names and mount points >> +filter_pool() >> +{ >> + sed -e "s|${devs[0]}|DEV1|g" -e "s|$mnt1|MNT1|g" \ >> + -e "s|${devs[1]}|DEV2|g" -e "s|$mnt2|MNT2|g" | _filter_spaces >> +} >> + >> +# Core helper to set IMA policy and check measurement logs >> +do_ima() >> +{ >> + local ima_policy="/sys/kernel/security/ima/policy" >> + local ima_log="/sys/kernel/security/ima/ascii_runtime_measurements" >> + local fsuuid >> + local mnt=$1 >> + local enable=$2 >> + >> + # Since the in-memory IMA audit log is only cleared upon reboot, >> + # use unique random filenames to avoid log collisions. >> + local foofile=$(mktemp --dry-run foobar_XXXXX) >> + >> + echo $mnt $enable | filter_pool >> + >> + [ -w "$ima_policy" ] || _notrun "IMA policy not writable" > > How about a _require_security_ima to make sure there's securityfs > and IMA supporting in current kernel. > sure. added. _require_security_ima() { [ -d /sys/kernel/security ] || _notrun "kernel doesn't support securityfs" # securityfs may not be mounted yet on the host; mount it # in a scratch location just to probe for IMA support. local se_mnt="${TEST_MNT}/${seq}/se_mnt" local has_ima=1 mkdir -p "${se_mnt}" _mount -t securityfs securityfs "${se_mnt}" 2>/dev/null || _notrun "cannot mount securityfs" [ -d "${se_mnt}/ima" ] || has_ima=0 [ -w "${se_mnt}/ima/policy" ] || _notrun "IMA policy not writable" _unmount "${se_mnt}" [ $has_ima -eq 1 ] || _notrun "kernel doesn't support IMA" } >> + >> + fsuuid=$(blkid -s UUID -o value ${devs[0]}) >> + >> + # Load IMA policy to measure file access specifically for this >> + # filesystem UUID. >> + if [[ $enable -eq 1 ]]; then >> + echo "measure func=FILE_CHECK fsuuid=$fsuuid" > "$ima_policy" || \ > > I'm not sure if we should have this test, especially add it into > auto and quick group. Once an IMA policy is loaded, there is no way to > clear or roll it back, and I am concerned it might potentially interfere > with subsequent tests. > Removed quick and auto. Looks like we need to gate it behind an opt-in group or restrict it to disposable/reboot-per-run environments. New group? I'm concerned it's getting too complicated and I see no other choice. > Hmm... how about use `unshare` command to rewrite the do_ima as do_ima_in_ns? > For example: > do_ima_in_ns() > { > ... > > unshare -U -m -p --fork --map-root-user bash < mount -t securityfs securityfs /sys/kernel/security > ima_policy="/sys/kernel/security/ima/policy" > ima_log="/sys/kernel/security/ima/ascii_runtime_measurements" > echo "measure func=FILE_CHECK fsuuid=$uuid" > "\$ima_policy" || exit 1 > ... > EOF > ret=$? > } A new namespace doesn't help undo the loaded IMA policy; I don't see the point of using unshare. I have the following code using unshare, which works fine. I dropped -U and --map-root-user (since fstests needs to run as root). I'm okay with including unshare, but I still don't see why. -------- unshare -m -p --fork bash <<-EOF | filter_pool | sed "s/$foofile/FOOBAR_FILE/" ima_policy="/sys/kernel/security/ima/policy" ima_log="/sys/kernel/security/ima/ascii_runtime_measurements" mount -t securityfs securityfs /sys/kernel/security || exit 1 # Load IMA policy to measure file access specifically for this # filesystem UUID. if [ $enable -eq 1 ]; then echo "measure func=FILE_CHECK fsuuid=$fsuuid" > "\$ima_policy" || exit 1 fi # Create a file to trigger measurement and verify its entry in # the IMA log. echo "test_data" > $mnt/$foofile # IMA log extract grep $foofile "\$ima_log" | awk '{ print \$5 }' echo "dbg: $mnt $fsuuid $foofile" >> $seqres.full tail -1 "\$ima_log" >> $seqres.full echo >> $seqres.full EOF -------- Thanks. > > Thanks, > Zorro > >> + _notrun "Policy rejected" >> + fi >> + >> + # Create a file to trigger measurement and verify its entry in >> + # the IMA log. >> + echo "test_data" > $mnt/$foofile >> + >> + # IMA log extract >> + grep $foofile "$ima_log" | awk '{ print $5 }' | filter_pool | \ >> + sed "s/$foofile/FOOBAR_FILE/" >> + >> + echo "dbg: $mnt $fsuuid $foofile" >> $seqres.full >> + cat $ima_log | tail -1 >> $seqres.full >> + echo >> $seqres.full >> +} >> + >> +# Initialize loop base and cloned instances >> +devs=() >> +_loop_image_create_clone devs >> +mnt1=$TEST_DIR/$seq/mnt1 >> +mnt2=$TEST_DIR/$seq/mnt2 >> +mkdir -p $mnt1 >> +mkdir -p $mnt2 >> + >> +# Concurrently mount both clones >> +_mount $(_common_dev_mount_options) $(_clone_mount_option) ${devs[0]} $mnt1 || \ >> + _fail "Failed to mount dev1" >> +_mount $(_common_dev_mount_options) $(_clone_mount_option) ${devs[1]} $mnt2 || \ >> + _fail "Failed to mount dev2" >> + >> +# IMA response on baseline and clone configuration >> +do_ima $mnt1 1 >> +do_ima $mnt2 0 >> + >> +# Cycle mount on the second device. >> +echo mount cycle >> +_unmount $mnt2 >> +_mount $mount_opts ${devs[1]} $mnt2 || _fail "Failed to mount dev2" >> + >> +do_ima $mnt1 0 >> +do_ima $mnt2 0 >> + >> +status=0 >> +exit >> diff --git a/tests/generic/804.out b/tests/generic/804.out >> new file mode 100644 >> index 000000000000..9804181d6c17 >> --- /dev/null >> +++ b/tests/generic/804.out >> @@ -0,0 +1,10 @@ >> +QA output created by 804 >> +MNT1 1 >> +MNT1/FOOBAR_FILE >> +MNT2 0 >> +MNT2/FOOBAR_FILE >> +mount cycle >> +MNT1 0 >> +MNT1/FOOBAR_FILE >> +MNT2 0 >> +MNT2/FOOBAR_FILE >> -- >> 2.43.0 >>